1-Azadiene complexes of zirconocene

Rearrangements and Stereomutations of Metallacycles Derived from Allenes and Imidozirconium Complexes

“…Several attempts to crystallize 9 to analytical purity were unsuccessful. 1 H NMR (C 6 D 6 , 500 MHz): δ 7.05 (d, J H 11 ), 28.1 (C 6 H 11 ), 27.6 (C 6 H 11 ), 27.5 (C 6 H 11 ), 27.0 (C 6 H 11 ), 27.0 (C 6 H 11 ), 22 To a solution of Cp 2 Zr=N(2,6-i-Pr 2 C 6 H 3 )(THF) 52 (0.082 g, 0.18 mmol) in toluene/pentane (1 mL/9 mL) was added a solution of 5a (0.033 g, 0.18 mmol) in pentane (2 mL). After 20 min at room temperature, the resulting deep blue solution was concentrated to dryness.…”

Diastereoselective Synthesis of Highly Substituted Five-Membered-Ring Oxygen Heterocycles by Zirconocene-Mediated C-C Coupling Reactions

“…This new practical route to the heterocycles in the title provides building blocks for the synthesis of natural products and biologically active substances such as alkaloids, macrocyclic antibiotics, lignans, pheromones, and fragrances. [5] Inspired by the work of Whitby et al [6] and Scholz et al, [7] we investigated the use of zirconocene-1-aza-1,3-diene complexes as homoenolate equivalents [8] in stereoselective synthesis. Scholz et al had shown that acetophenone inserts into the Zr ± C s bond of 2,2-bis(h 5 -cyclopentadienyl)-1-(2-methylphenyl)-3-phenyl-1-aza-2-zircona-4-cyclopentene (2).…”

Insertion of Nitriles into Zirconocene 1‐aza‐1,3‐diene Complexes: Chemoselective Synthesis of N–H and N‐Substituted Pyrroles

“…In this regard, zirconocene complexes of 1‐aza‐1,3‐dienes,2, 3 first reported by Whitby et al. in 1991,2a are attractive synthetic precursors for selective transformations. Based on X‐ray crystal analysis, these complexes are described as σ 2 ,π‐azazirconacyclopentenes ( A ) with a folded five‐membered‐ring moiety rather than η 4 ‐azadiene complexes ( B ) 2b,i.…”